With the increasing prevalence and capability of digital imaging techniques, imaging bar code scanning is gaining increasing interest as a mechanism for bar code scanning. Imaging scanning allows for significant simplification of scanner design and construction by avoiding complex laser and optical components used in conventional bar code scanners.
Conventional laser bar code scanners, particularly pass by scanners, frequently provide numerous differently oriented scan lines, so that one or more scan lines can be counted on to intersect bar codes presented in a variety of different orientations. Imaging bar code scanners, on the other hand, typically employ cameras which capture images with square or rectangular imaging devices arranged in one or more rows of data elements, or pixels, so that image information is distributed across a plurality of rows of data elements. Bar code information, that is, data indicating light and dark areas of a bar code image, appears in each of a plurality of rows across the array. Typical imaging bar code scanners often use imaging devices oriented such that the image of a bar code captured by an imaging device is orthogonal to the rows of pixels of the imaging device in a preferred orientation in which the bar code may be expected to be presented. An image captured by such a device is well adapted to processing if the lines and spaces of the bar code are orthogonal to the rows of pixels in the imaging device, but much less well adapted to processing if the lines and spaces are parallel to the rows of pixels.